L24: Sepsis, Failure Of Passive Transfer, And Fluid Therapy In Calves (Reuss) Flashcards
Infection in sepsis can be:
- bacteremia, viremia, fungemia, etc.
- endotoxemia: circulating LPS
- generalized or focal
- identified or suspected
Portals of entry for sepsis
- in utero
- ingestion (via non-selective pinocytosis, translocation of enteritis; most common)
- inhalation
- umbilical (uncommon)
Risk factors for developing sepsis
- failure of passive transfer
- lack of normal adult intestinal flora
- environmental
Etiology of sepsis
- E. Coli (>50%)
- Salmonella
- Campylobacter
- Klebsiella
- Listeria
- Staph/Strep
- Lepto
- Actinobacillus
Steps of sepsis
- Infection (invasion of normally sterile host tissue)
- Systemic inflammatory response
- Septic shock
- Multiple organ dysfx syndrome
CS of generalized sepsis
- altered mental status
- weakness
- lack of suckle
- abnormal TPR (fever or hypothermia)
- Diarrhea
- Acute death
- scleral injection
- petechiation, ecchy, hyperemia
- cold extremities, slow CRT, weak pulses
Local infections assoc. with sepsis
(Often sequelae to generalized infection)
-usually in older calves
Septic arthritis
Meningitis
Hypopyon
Pneumonia
Umbilical disorders
- urachus most commonly affected structure
- can cause systemic sepsis, or walled off internal abscesses in older calves
- abscesses can lead to fever, poor condition, dysuria, stranguria, colic +/- septic peritonitis if they rupture
Dx of sepsis
Blood culture Hematology: -leukopenia due to neutropenia -toxic neutrophils, degenerative L shift -leukocytosis with persistent infection -decreased (?) fibrinogen
Chemistry (hypoglycemia +/- hypoproteinemia)
Blood Gas
Misc: Thoracic rads, US, arthrocentesis, CSF aspirate
Explain chemistry changes in septic calf
Hypoglycemia (esp. In younger calves) since bacteria consuming glucose. Hypoproteinemia if failure of passive transfer.
Blood gas changes in septic calf
- Metabolic acidosis due to L and/or D lactate
- Hypoxemia
- Hypoventilation
Metabolic acidosis: young vs. old calves
- L lactate comes from calves and more common in younger calves, and D lactate comes from bacteria and more prevalent in older calves with greater bacterial flora in GIT.
- older calves will usually have worse acidemia and may need to be treated with bicarb, whereas younger calves can be treated with crystalloid fluids
Tx of sepsis
Abx:
- Ceftiofur = drug of choice (off label) because reaches MIC for E. Coli
- Ampicillin
- Florfenicol
- anti-inflammatory (flunixin)
- address failure of passive transfer
- fluid support
- nutritional support
- supportive care
Duration of abx tx for sepsis
7-10 days if sepsis suspected but undocumented
2 wks if + blood culture but not localized
3-4 wks if localized infection
Or until have normal WBC, fibrinogen, rads
Supportive care of septic calf
- warmth, good bedding
- oxygen, ventilation
- address decubital sores, urine scald, fecal scald
- postural changes, physical therapy
- ocular monitoring/tx
passive transfer
- epitheliochorial placentation doesn’t transfer Abs, WBCs
- calves are immunocompetent at birth and have protective Ab lvls at 30 days with maximal lvls at 2-3 mos.
- passive immunity impacts long-term production
Properties of colostrum
- secreted last 4-6 wks of pregnancy
- IgG > IgM, IgA
- offers local protection
- contains fat, protein, vitamins, minerals, lactoferrin, growth factors, mis. Immune factors
Absorption of colostrum
Nonselective pinocytosis by intestinal ep. –> lymphatics –> blood
- closure stimulated by ingestion of any material
- capacity 50% at 6 hrs, 33% at 8 hrs, 0 at 24 hrs
Delivery of colostrum
- 3-4 L of good quality should be delivered
- concentration should be >1.050
- delivered via natural sucking (60% have FPT!), bottle feeding (19% FPT), or esophageal feeder in one large volume (most successful with only 10% FPT)
Factors that effect transfer of IgG
- timing of colostral feeding
- colostral IgG
- dam parity
- volume fed
- method of administration
When to test for passive transfer
At 12-24 hrs, at least one in 1st few days
- detectable within 2 hrs of ingestion, and peaks at 32 hrs
- FPT does NOT guarantee disease, but DOES predispose to sepsis
Tests for FPT
1) Radial immunodiffusion (gold standard)
2) ELISA
3) Sodium Sulfite Turbidity Test
4) Zinc Sulfate Turbidity Test
5) Serum TP
6) Serum GGT
7) Glutaraldehyde coagulation test
Radial immunodiffusion test for FPT
Gold standard
- requires 24 hrs to perform
- IgG >1000 = success
Sodium Sulfite Turbidity Test for FPT
- rapid, cost-effective, stall side
- use 14/16/18% solutions and look for precipitation
- precipitation at lower % solutions indicates higher Ab
-has fewer false positives that zinc sulfate turbidity test
Serum total protein test for FPT
> 5.2 g/dl = adequate transfer if healthy
5.5 = adequate transfer if ill
*falsely increased by dehydration
Serum GGT test for FPT
GGT should be >200 U/L at 24 hrs
Glutaraldehyde coag. test for FPT
10% reagent coagulates with serum IgG >600
*Poor Sp/Se
ELISA test for FPT
- stall side, blood or plasma
- should be >10 mg/ml IgG
Treatment of FPT
In first 12 hrs, give colostrum or colostrum replacer:
-2L replacer at 2 hrs + dose of supplement at 2-12 hrs –> successful PT
After 12 hrs, give plasma or whole blood transfusion
- don’t transfuse from dam (won’t have good Ab)
- not imperative to crossmatch
-Fluids, Nutritional support
Colostrum supplement properties
- comes from bovine colostrum, milk products, or serum
- 40-60 g IgG/dose
- can’t raise IgG above 1000 mg/dl
- utilized when only low medium quality colostrum available
Colostrum REPLACER properties
- made from bovine serum or colostrum based products
- contain at least 100g IgG per liter + fat, protein, vitamins, minerals
- better than poor quality colostrum
- less risk of Johnes transmission
*high quality maternal colostrum still gold standard!
Goals of fluid therapy for FPT
Correct:
- hypovolemia
- hypoglycemia
- metabolic acidosis
- electrolyte abnormalities
1-5% dehydration CS
Eyes not or slightly sunken
Skin tent 1-4 s
Membranes moist
6-8% dehydration CS
Eyes slightly sunken
Skin tent 5-10s
Membranes tacky but calf still suckling
9-10% dehydration CS
Eyes sunken
Skin tent 11-15s
Membranes tacky to dry
Calf depressed
11-12% dehydration CS
Eyes very sunken
Skin tent 16-45s
Membranes dry
Calf can’t stand and is severely depressed
Fluid calculation
Replacement + Maintenance + Ongoing losses
Replacement = % dehydration x BW Maintenance = 75-100 mls/kg/day
IV fluids indications
More than 8% BW decrease Severe CNS depression Inability to stand Not suckling >24h Body temp
Fluid choices for septic calf
- Balanced crystalloids best (LRS, Normosol, Plasmalyte)
- Physiologic saline will acidify them
- Colloids: plasma, whole blood, hetastarch
- Hypertonic saline not good for neonates b/c will throw off Na
Fluid supplementations
1) Dextrose: 2.5-5% for hypoglycemia
2) Bicarb for D-lactic acidosis in older calves >8 days**
- should monitor pH, HCO3, TCO2
Calculation for how much bicarb to give
BW x 0.5 x (24 - measured HCO3)
Indications for oral fluids (vs. IV)
- ambulatory
- functional GIT
*is cost effective and can be done on the farm. Can give following IV fluids/bicarb, and in place of milk for short durations
Types of oral electrolyte solution
- depend on degree of acidosis and electrolyte abnormalities what type you give
- most contain Na, Cl, K, glucose, glycine
- if osmolarity is too low, won’t have enough glucose for energy
- if osmolarity to high, will slow abomasal emptying rate
- avoid >145 mmol Na/L (has no alkalinizing agent)
Oral alkalinizing agents
1) Bicarb (curdles milk)
2) Acetate (best)
- doesn’t interfere w/ milk clotting, produces energy when metabolized, facilitates Na and water absorption in SI, and doesn’t alkalinize the abomasum
3) Proprionate
- also doesn’t interfere w/ milk clotting
Nutritional support for septic calf
- if unwilling to suckle, start tubing with 10-15% BW/24 hrs over 3-5 feedings
- if bloated, provide parenteral nutrition
- use cows milk/replacers
